Single OTRA Based Universal Third Order Butterworth Filter and Its Performance Study.

In this paper the authors have proposed a universal third order Butterworth filter using a single operational transresistance amplifier (OTRA) and few passive elements. The proposed design can be reconfigured to realize low pass (LP), band pass (BP), band reject (BR), high pass (HP), and all pass (AP) filter operations by changing some switch state. Various analysis of performance like noise analysis, temperature analysis, and worst case analysis of the proposed design are also presented. The simulations are carried out with 180 nm high performance CMOS based model of OTRA using SPICE simulator. Experimental verification of the proposed circuit has also been demonstrated with AD844AN IC confirming the authenticity of the work.